Premium
Monolithic Fabrication of NPN/SiN x Dual Membrane Cavity for Nanopore‐Based DNA Sensing
Author(s) -
Madejski Gregory R.,
Briggs Kyle,
DesOrmeaux JonPaul,
Miller Joshua J.,
Roussie James A.,
TabardCossa Vincent,
McGrath James L.
Publication year - 2019
Publication title -
advanced materials interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.671
H-Index - 65
ISSN - 2196-7350
DOI - 10.1002/admi.201900684
Subject(s) - nanopore , materials science , fabrication , wafer , silicon nitride , nanotechnology , nanoscopic scale , silicon , optoelectronics , substrate (aquarium) , nanoporous , nanometre , microfluidics , composite material , medicine , oceanography , alternative medicine , pathology , geology
Nanoscale preconfinement of DNA is shown to reduce the variation of passage times through solid‐state nanopores. Preconfinement is previously achieved by forming a femtoliter‐sized cavity capped with a highly porous layer of nanoporous silicon nitride (NPN). This cavity is formed by sealing a NPN nanofilter membrane against a substrate chip using water vapor delamination. Ultimately, this method of fabrication cannot keep a consistent spacing between the filter and solid‐state nanopore due to thermal fluctuations and wrinkles in the membrane, nor can it be fabricated on thousands of individual devices reliably. To overcome these issues, a method is presented to fabricate the femtoliter cavity monolithically, using a selective xenon difluoride (XeF 2 ) etch to hollow out a polysilicon (poly‐Si) spacer sandwiched between silicon nitride (SiN x ) layers. These monolithically fabricated cavities behave identically to their counterparts formed by vapor delamination, exhibiting similar translocation passage time variation reduction and folding suppression of DNA without requiring extensive manual assembly. The ability to form nanocavity sensors with nanometer‐scale precision and to reliably manufacture them at scale using batch wafer processing techniques will find numerous applications, including motion control of polymers for single‐molecule detection applications, filtering of dirty samples prior to nanopore detection, and simple fabrication of single‐molecule nanobioreactors.